The present disclosure relates generally to a system and method for reducing emissions from a combustion engine and particularly to a system and method for reducing emissions from a combustion engine by enriching the combustion fuel with hydrogen-containing gas.
Current technologies for reducing emission of toxic gases, such as NOx from reciprocating engines using natural gas as fuel, rely on lean combustion. Lean combustion reduces the peak temperatures within the cylinders in the engine, and hence reduces the production of NOx. Gases such as NOx are formed by reactions between nitrogen and oxygen in air that is used for combustion in an engine. Formation of NOx strongly depends on the temperature of combustion. Due to low flame speed of natural gas, there are limits to lean combustion without affecting combustion stability. Other methods of NOx reduction involve use of after-treatment technologies that are costly and can have reliability issues when used with fuels other than natural gas. Hydrogen enrichment of a fuel is another way for reducing the production and emission of NOx.
Hydrogen gas, used for enrichment of a fuel prior to combustion, may be produced in different routes including external partial oxidation reactor, external steam reformer, electrolyzer etc. However, storing and delivering the hydrogen gas required for enrichment of the combustion fuels increase the cost of a combustion system and also raises safety issues.
Therefore there is a need for a combustion engine system, which system can produce hydrogen safely and efficiently for the purpose of hydrogen enrichment of the combustion fuel.